Active optical networks (AONs) have been one of the most deployed fiber access solutions in Europe. With increasing traffic demand, the capacity of existing AONs is becoming insufficient. For legacy AONs, there are two major variants of architectures: point-to-point and active star. Considering the different characteristics of these two AON architectures, this paper proposes and analyzes several migration paths toward next-generation optical access (NGOA) networks offering a minimum 300 Mbit/s sustainable bit rate and 1 Gbit/s peak bit rate to every end customer.